/**
 * react-redux hooks
 * - useDispatch 获取dispatch方法
 * - useSelector 获取state
 * - useStore 获取store对象
 *
 * reducers
 * - combineReducers 合并reducer
 *
 * redux-thunk 异步
 * - 中间件
 * - applyMiddleware 接收中间件
 */